AI Crawlers Explained — What Bots Read Your Site and Why
TL;DR
Six major AI crawlers regularly visit websites: GPTBot (OpenAI), Claude-Web (Anthropic), Google-Extended, PerplexityBot, Bytespider (ByteDance), and Amazonbot. They differ from search crawlers in purpose, frequency, and what they extract. AI crawlers prioritize passage-level content extraction over link-graph building. Blocking them protects your content from uncompensated training but removes you from AI search results. Most brands should use selective blocking, not total exclusion.
The Shift from Search Bots to AI Crawlers
For 25 years, SEO meant optimizing for Googlebot. You worried about crawl budget, internal linking, and page speed because Googlebot needed to discover, index, and rank your pages.
AI crawlers play a different game. They do not build a link graph. They extract passages, facts, and entities. Their goal is not to return a list of links. Their goal is to synthesize an answer.
This changes everything about what matters on your site.
| Search Crawlers | AI Crawlers | |
|---|---|---|
| Primary goal | Index pages for search results | Extract content for training / synthesis |
| What they read | HTML, CSS, JavaScript | HTML, text content, transcripts |
| What they value | Links, authority, relevance | Passages, facts, entities, structure |
| Frequency | Daily to weekly | Highly variable; some daily, some monthly |
| Respects robots.txt | Yes | Sometimes (varies by bot) |
| Result for you | Ranking position | Inclusion in AI-generated answers |
The Major AI Crawlers (Detailed Breakdown)
1. GPTBot (OpenAI)
User-agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.0; +https://openai.com/gptbot)
Purpose: Training data collection for GPT-4, GPT-4o, and future models. Also used for ChatGPT browsing.
Frequency: Moderate. Spikes before major model releases.
Opt-out: Disallow: / in robots.txt for GPTBot, or use OpenAI's opt-out form.
What it extracts: Full page text, with emphasis on structured content (lists, tables, FAQ sections).
2. Claude-Web (Anthropic)
User-agent: Claude-Web/1.0 (Anthropic AI assistant; +https://www.anthropic.com/claude-web)
Purpose: Research and citation for Claude's responses. Less training-focused, more real-time knowledge acquisition.
Frequency: Low to moderate. Tends to visit high-authority domains.
Opt-out: robots.txt blocking for Claude-Web user-agent.
What it extracts: Passage-level content with high preference for academic, research, and news sources.
3. Google-Extended
User-agent: Google-Extended (used alongside standard Googlebot)
Purpose: Training data for Gemini, Bard, and AI Overviews.
Frequency: High. Shares infrastructure with Googlebot.
Opt-out: Google-Extended block in robots.txt, or use Google Search Console's AI training control.
What it extracts: Similar to Googlebot but with additional extraction of passages for direct answer generation.
4. PerplexityBot
User-agent: Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexity-bot)
Purpose: Real-time search indexing for Perplexity's answer engine.
Frequency: High. Perplexity aims for near real-time answers.
Opt-out: robots.txt blocking.
What it extracts: Fresh content with emphasis on news, data, and authoritative sources. Prioritizes recency over authority.
5. Bytespider (ByteDance)
User-agent: Bytespider
Purpose: Training data for Doubao (China) and potential TikTok AI features.
Frequency: Moderate and increasing.
Opt-out: robots.txt blocking.
What it extracts: Broad web content with multilingual emphasis.
6. Amazonbot
User-agent: Mozilla/5.0 (compatible; Amazonbot/1.0; +https://developer.amazon.com/support/amazonbot)
Purpose: Training for Alexa and Rufus (Amazon's AI shopping assistant).
Frequency: Moderate. E-commerce sites see more visits.
Opt-out: robots.txt blocking.
What it extracts: Product descriptions, reviews, pricing, and comparison content.
Comparison Table
| Bot | Company | Purpose | Frequency | robots.txt Respect |
|---|---|---|---|---|
| GPTBot | OpenAI | Training + browsing | Moderate | Yes |
| Claude-Web | Anthropic | Research + citation | Low-Moderate | Yes |
| Google-Extended | Gemini + AI Overviews | High | Yes | |
| PerplexityBot | Perplexity | Real-time search | High | Yes |
| Bytespider | ByteDance | Doubao / TikTok AI | Moderate | Partial |
| Amazonbot | Amazon | Alexa + Rufus | Moderate | Yes |
How AI Crawlers Differ from Search Crawlers
Content extraction vs link graph building
Googlebot cares about who links to you. AI crawlers care about what you say.
A page with zero backlinks but exceptional passage-level content can be heavily cited by LLMs. A page with 1,000 backlinks but thin content will rank well on Google and be ignored by AI systems.
Passage-level parsing vs page-level indexing
Search engines index the whole page. AI crawlers often extract individual passages.
This is why the 134–167 word self-contained answer block is so effective. It is the exact unit of content that AI crawlers extract and LLMs synthesize.
Freshness priority
AI crawlers — especially PerplexityBot and browsing-enabled systems — prioritize fresh content. A news article from today is more valuable than an evergreen guide from 2023, even if the guide is more comprehensive.
How to Control What AI Crawlers See
robots.txt rules per bot
The standard approach is user-agent-specific rules:
User-agent: GPTBot
Disallow: /internal/
Disallow: /drafts/
Allow: /
User-agent: Claude-Web
Disallow: /internal/
Allow: /
User-agent: Google-Extended
Disallow: /internal/
Allow: /
User-agent: PerplexityBot
Disallow: /internal/
Allow: /
This allows crawlers to access your public content while protecting internal or draft pages.
Noindex for training (not reliable)
The noindex meta tag tells search engines not to index a page. It does not reliably prevent AI crawlers from using the content for training. Some crawlers may respect it; others may not.
Terms of Service approaches
Some companies are adding clauses to their Terms of Service prohibiting AI training use of their content. This is legally untested but sends a clear signal. Enforcement is difficult.
Contractual approaches
Reddit, Stack Overflow, and several news publishers have signed direct licensing deals with AI companies. This is the most reliable protection — but only available to large platforms.
Should You Block AI Crawlers?
Arguments for blocking
- Protect intellectual property. Your content may be used to train models without compensation.
- Prevent misrepresentation. LLMs sometimes hallucinate or misattribute content.
- Competitive advantage. If competitors train on your content, they learn your strategy.
Arguments against blocking
- Lose AI search visibility. If you block PerplexityBot, you will not appear in Perplexity answers.
- Forfeit citation opportunities. LLMs cannot cite sources they do not know exist.
- Training data is already collected. For base models, blocking future crawls does not remove already-ingested data.
The middle path: selective blocking
Most brands should use this strategy:
- Allow all AI crawlers on public marketing content, blog posts, research, and product pages.
- Block AI crawlers from internal documentation, draft content, pricing negotiations, and customer data.
- Monitor crawler traffic to detect abuse or excessive frequency.
This maximizes visibility while protecting sensitive content.
Monitoring AI Crawler Traffic
Log analysis
Search your server logs for the user-agent strings listed above. Look for:
- Frequency of visits per bot
- Pages accessed
- Time between visits
- Unusual patterns (e.g., rapid-fire requests)
SIQA's crawler detection
Our platform includes a crawler detection module that:
- Identifies AI crawler visits in real time
- Alerts on excessive frequency
- Compares your crawler exposure to industry benchmarks
- Recommends robots.txt adjustments
FAQ
Do AI crawlers respect robots.txt?
Most do, but not all. OpenAI, Google, and Anthropic explicitly state that their crawlers respect robots.txt. Smaller or less transparent bots may not. robots.txt is a request, not an enforceable barrier.
Can I charge AI companies for crawling?
Not through technical means. Some publishers are negotiating licensing deals directly with AI companies. This requires legal resources and significant traffic volume.
What's the difference between training and browsing?
Training means using your content to build the model's base knowledge. Once ingested, it is part of the model permanently (until retraining). Browsing means the model accesses your live site for a specific query. Browsing does not permanently add your content to the model.
How do I identify AI crawler traffic in my logs?
Search for the user-agent strings listed in the comparison table above. Most analytics platforms (Google Analytics, Plausible) do not categorize AI crawlers separately. You need server log access.
Will blocking crawlers hurt my SEO?
No. robots.txt rules for AI crawlers do not affect Googlebot or Bingbot. Your search rankings are unaffected.
The Future of AI Crawling
Real-time APIs replacing crawl
The current crawl-based model is inefficient. In the next 2–3 years, we expect AI companies to shift toward real-time APIs and structured data feeds. Brands that maintain clean APIs, schema markup, and llms.txt will be best positioned for this transition.
Content licensing models
As legal pressure increases, AI companies will likely move toward licensed content partnerships. Early movers — brands with clear Terms of Service and direct relationships — will capture value.
What you should do now
- Audit your robots.txt for AI crawler rules
- Decide your blocking strategy (allow all, block all, or selective)
- Implement the strategy
- Monitor crawler traffic monthly
- Prepare for the API-first future with schema markup and structured data
See which AI crawlers visit your site →
Published by SIQA Editorial Team. Crawler data collected from server log analysis across 500+ domains, January–April 2026.